Comprehensive report of an Enterococcus cecorum infection in a broiler flock in Northern Germany.
Comprehensive report of an Enterococcus cecorum infection in a broiler flock in Northern Germany.
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DOI：
10.1186/s12917-014-0311-7
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发表时间：
2014-12-24
影响因子：
2.6
通讯作者：
Rautenschlein S
中科院分区：
文献类型：
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作者：
Jung A;Rautenschlein S
盲肠肠球菌被认为是家禽中的一种新出现的病原体，并且可以造成肉鸡群的重大损失。股骨头坏死和脊柱炎是感染鸡的主要病理变化。然而，关于盲肠肠球菌感染肉鸡的发病机制知之甚少。该报告首次显示了整个生长期的整个疾病过程，包括反复尸检和随后的微生物调查。在一群18200只肉鸡中，从孵化后14天开始检测到群均匀性降低，受影响的鸡显示跛行，并在孵化后第33天群死亡率增加至7.22%。在出雏后3周内，心包炎和肝炎分别占被检鸡的27.6%和9.8%。生长期最后一周出现股骨头坏死和椎体骨髓炎的发生率分别为10.3%和2.3%。对59只病鸡的心、肝、脾、卵黄囊和脊柱进行了细菌学分析。从23只鸡（39%）中分离到盲肠肠球菌，第一只鸡在孵化后第3天卵黄囊中已呈阳性。此外，9.75%的肉鸡主要由于病理变化而被屠宰场拒收。与同一鸡场盲肠肠球菌感染前7个周期和感染后4个周期相比，所研究的肉鸡周期具有迄今为止最好的足垫评分。菌血症和全身感染是盲肠肠球菌感染发病的重要环节。此外，这种疾病不仅由于鸡群死亡率的增加，而且还可能由于屠宰场的高得多的报废率而给农民造成经济损失。据推测，肉鸡是通过呼吸道感染的，因为这群鸡的脚垫评分较低，这可能是由于垫料干燥的结果。后者可能导致更高的粉尘浓度，从而导致空气中的盲肠肠球菌。
Enterococcus cecorum is considered as an emerging pathogen in poultry and can cause substantial losses in broiler flocks. Femoral head necrosis and spondylitis were described as the main pathological changes in infected chickens. Nevertheless, little is known about the pathogenesis of Enterococcus cecorum infection in broilers. This report shows for the first time the whole course of disease over an entire growing period including repeated necropsies and subsequent microbiological investigations. In a flock of 18200 broilers, a decrease in flock uniformity was detected from 14 days post hatch onwards with affected chickens showing lameness and an increase in flock mortality up to 7.22% at day 33 post hatch. In the first 3 weeks post hatch, pericarditis and hepatitis were found as the main pathological changes in 27.6% and 9.8% of the examined broilers respectively. Femoral head necrosis and vertebral osteomyelitis were detected in the last week of the growing period with 10.3% and 2.3% respectively. Heart, liver, spleen, yolk sac and vertebral column of 59 broilers with pathological changes were subjected to bacteriological analysis. Enterococcus cecorum was isolated from 23 birds (39%), the first broiler was already positive at day 3 post hatch in the yolk sac. Additionally, 9.75% of the broilers were rejected at the slaughterhouse primarily because of pathological changes. The investigated broiler cycle had by far the best footpad score compared to 7 cycles before and 4 cycles after the Enterococcus cecorum infection at the same farm. Bacteraemia and generalized infection appear to be important steps in the pathogenesis of Enterococcus cecorum infection in broilers. Furthermore, this disease causes economic losses for the farmer not only due to an increase in flock mortality, but probably also through substantially higher condemnation rates at the slaughterhouse. It was speculated that the broilers were infected via the respiratory tract as this flock had lower footpad scores likely the result of drier litter. The latter may have led to higher dust concentrations and thus airborne Enterococcus cecorum.